JP2014141408A - Hydrogen sulfide gas production plant system and method for recovering and using a hydrogen sulfide gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an effective supply of a hydrogen sulfide gas by efficiently recovering a low-concentration hydrogen sulfide gas generated at the time of the periodic checkup or the start-up of a production plant and by properly controlling the supply of the hydrogen sulfide gas into a processing plant using the same.SOLUTION: The provided hydrogen sulfide gas production plant is furnished with: a first supply pipeline 14 for supplying, into a processing plant X, a hydrogen sulfide gas obtained from a sulfur recovery facility 13; and a second supply pipeline 16 branching from a specified site 15 of the first supply pipeline 14 for feeding the hydrogen sulfide gas from the sulfur recovery facility 13 into the processing plant X. A concentration meter 22 for measuring the hydrogen sulfide gas concentration is configured within the first supply pipeline 14 on the upstream side of the branching site 15, whereas ON/OFF valves 23 and 26 for executing ON/OFF controls of the supply into the processing plant X mediated by the first supply pipeline 14 and second supply pipeline 16 are configured within the respective pipelines on the downstream side of the branching site 15. A control valve is configured between the specified branching site 15 and the ON/OFF valve 26 configured on the second supply pipeline 16.

Description

  The present invention relates to a hydrogen sulfide gas production plant and a method for recovering and using waste hydrogen sulfide gas. More specifically, the present invention can recover discharged hydrogen sulfide gas and supply it to a processing plant that uses hydrogen sulfide gas. The present invention relates to a hydrogen sulfide gas production plant and a method for recovering and using waste hydrogen sulfide gas by the hydrogen sulfide gas production plant.

  For example, in the hydrometallurgical method of nickel oxide ore, hydrogen sulfide gas is blown into the solution obtained by neutralizing the leachate of nickel oxide ore and the solution for recovering nickel from which impurities have been removed. Sulfurization treatment is performed.

  The hydrogen sulfide gas used at this time is manufactured by, for example, a hydrogen sulfide gas manufacturing plant having a configuration as shown in FIGS.

  Specifically, the hydrogen sulfide gas production plant 50 shown in FIG. 3 includes a reaction facility 51 that generates hydrogen sulfide gas from supplied sulfur and hydrogen gas, a cooling facility 52 that cools the hydrogen sulfide gas, and a hydrogen sulfide gas. A cleaning facility 53 for cleaning sulfur contained therein, and a drying facility 54 for drying the hydrogen sulfide gas after cleaning to remove moisture. Further, the hydrogen sulfide gas production plant 50 includes a storage facility 55 that stores the generated hydrogen sulfide gas and a supply facility 56 that supplies the hydrogen sulfide gas as ancillary facilities.

  In the hydrogen sulfide gas production plant 50, a catalyst is used in the reactor 51 for the purpose of reducing activation energy. Further, in the hydrogen sulfide gas production plant 50, the sulfur contained in the produced hydrogen sulfide gas is removed by the cleaning equipment 53, and then the moisture is removed by the drying equipment 54, thereby preventing the equipment from being corroded by moisture.

  Further, in the hydrogen sulfide gas production plant 50, the produced hydrogen sulfide gas is boosted to a required pressure using a supply facility 56 such as a compressor, and the pressurized hydrogen sulfide gas is made from, for example, the above-described nickel oxide ore wet-made. Supplied to a plant that uses hydrogen sulfide gas in the dezincing process or sulfiding process of the smelting method.

  The hydrogen sulfide gas production plant 50 is operated at a pressure of about 5 kPaG and a temperature of about 380 ° C. as conditions for producing the hydrogen sulfide gas. In the hydrogen sulfide gas production plant 50, since a catalyst is used for the reaction equipment 51, it is possible to operate under conditions where both pressure and temperature are low, which is an operational advantage.

  However, in the hydrogen sulfide gas production plant 50, in addition to the need to periodically replace the catalyst in the reaction facility 51, the quality of sulfur, which is a raw material for hydrogen sulfide gas, is strictly controlled from the viewpoint of the life of the catalyst. There is a need to.

  On the other hand, the hydrogen sulfide gas production plant 60 shown in FIG. 4 is a plant that does not use a catalyst in the reactor. As shown in FIG. 4, the hydrogen sulfide gas production plant 60 includes a reaction facility (reactor 66, quench tower 67, heater 68) 61 that generates hydrogen sulfide gas from sulfur and hydrogen gas, and cooling that cools the hydrogen sulfide gas. Facility 62 (62A, 62B), knockout facility 63 for removing sulfur in hydrogen sulfide gas and supplying hydrogen sulfide gas, and blowdown facility 64 for recovering sulfur removed from hydrogen sulfide gas and supplying it to a sulfur treatment plant or the like It consists of and. In addition, the hydrogen sulfide gas production plant 60 includes, as ancillary equipment, equipment 65 that cools the temperature of sulfur in order to adjust the heat balance.

  In the hydrogen sulfide gas production plant 60, molten sulfur is stored in the reactor 66 of the reaction facility 61, and hydrogen gas is supplied from the lower portion, so that the generation reaction of hydrogen sulfide gas proceeds while the hydrogen gas passes through the molten sulfur. To do. In addition, sulfur reduced by the reaction is supplied from the upper part of the reaction facility 61. Although most of the hydrogen sulfide gas generated in the reaction facility 61 is hydrogen sulfide, it contains sulfur vapor that is entrained when the hydrogen gas passes through the reactor.

  Further, the hydrogen sulfide gas production plant 60 is operated under conditions of high temperature and high pressure such as a pressure of about 800 kPaG and a temperature of about 470 ° C. as conditions for producing the hydrogen sulfide gas. The generated hydrogen sulfide gas is lowered to a temperature of about 150 ° C. when it exits the quench tower 67 constituting the reaction facility 61, and is further about 50 ° C. in the cooling facility 62 (used in the supply destination facility). Temperature) and transferred to the knockout facility 63.

  Further, most of the sulfur contained in the hydrogen sulfide gas generated in the reaction facility 61 is made up of valves such as control valves and manual valves in plants that use the hydrogen sulfide gas to be supplied, thermometers and pressure gauges. If it adheres to the instruments such as, it will cause a big trouble in operation. Therefore, it is solidified once in the knockout facility 63, and the sulfur deposited on the bottom thereof is melted and recovered by heating with steam through a jacket installed around the lower part of the knockout facility 63. The recovered sulfur is stored in the blow-down facility 64 and then supplied to the sulfur treatment plant using the supply pump 69 to be processed or repeatedly used.

  Thus, after the sulfur contained in the hydrogen sulfide gas produced | generated in the hydrogen sulfide gas manufacturing plant 60 was isolate | separated with the knockout drum, the hydrogen sulfide gas is the hydrometallurgy method of the nickel oxide ore mentioned above, for example Supplied to a plant that uses hydrogen sulfide gas in the dezincing process, sulfiding process, and the like.

  Since the hydrogen sulfide gas production plant 60 is operated and managed with the pressure in the system being high, facilities such as a compressor and a chiller facility become unnecessary, and initial investment can be suppressed. Further, there is an advantage that the operation cost can be reduced because the periodic replacement of the catalyst as in the hydrogen sulfide gas production plant 50 described above, the replacement cost for the catalyst, and the maintenance cost including the quality control of sulfur are unnecessary.

  However, since the hydrogen sulfide gas production plant 60 operates under conditions of high pressure and high temperature, when supplying the produced hydrogen sulfide gas, the hydrogen sulfide gas production plant 60 can be depressurized to an appropriate pressure in the plant operation of the supply destination. I need it. For example, in a plant in a sulfidation process in which nickel oxide ore is processed to produce a mixed sulfide (mixed sulfide: MS) containing nickel and cobalt, hydrogen sulfide gas is operated at a pressure of about 350 kPaG. In the plant in the dezincing step in which zinc contained in the neutralized final solution is converted into zinc sulfide, the hydrogen sulfide gas is operated at a pressure of about 5 kPaG or less. Further, since the hydrogen sulfide gas production plant 60 is operated under conditions of high pressure and high temperature, there is a high risk of gas leakage, and hydrogen sulfide gas that is a facility for cooling sulfur (sulfur vapor) contained in hydrogen sulfide gas. The load on the cooling facility 62 and the knockout facility 63, which is a facility for recovering hydrogen sulfide gas, increases.

  Further, in the hydrogen sulfide gas production plant 60, sulfur contained in the generated hydrogen sulfide gas is recovered and removed by the knockout facility 63, but a part of the sulfur is solidified in the cooling facility 62 and fixed inside thereof. If left as it is, the operation efficiency is lowered. Therefore, a plurality of cooling facilities are provided, and they are used by switching them alternately.

  Specifically, for example, two cooling facilities 62A and 62B are provided, and the cooling facility 62A used in the state where the cooling capacity is reduced due to sulfur fixed inside the cooling facility 62A (the state where the inside is fixed) And the standby cooling equipment 62B (equipment with the internal sticking removed). And it is set as a standby state by melt | dissolving and collect | recovering the sulfur adhering in an installation using steam about the cooling equipment 62A in which the cooling capacity fell. By repeating these operations, the operating rate of the hydrogen sulfide gas production plant 60 is prevented from decreasing. The sulfur melted and recovered by the cooling facility 62 (62A, 62B) is transferred to the blowdown facility 64 and processed in the same manner.

  By the way, in the hydrogen sulfide gas production plant 60, since the hydrogen sulfide gas production facility is operated under high pressure and high temperature conditions as described above, the malfunction of each control valve and ON / OFF valve and each instrument. It is considered that troubles such as leakage of hydrogen sulfide gas from hydrogen sulfide gas production facilities and incidental facilities and blockage of piping due to adhesion of sulfur contained in hydrogen sulfide gas are likely to occur.

  In order to prevent such troubles, it is necessary to periodically check the hydrogen sulfide gas production plant.

  When troubles such as those mentioned above occur or during periodic inspections, the hydrogen sulfide gas production plant and the processing plant using hydrogen sulfide gas are separated from each other by an ON / OFF valve or the like, and the inside of the hydrogen sulfide gas production plant Needs to be replaced with nitrogen gas. In addition, when any trouble occurs in a processing plant using hydrogen sulfide gas, it is necessary to cope with it by separating the hydrogen sulfide production plant from the processing plant using hydrogen sulfide gas by an ON / OFF valve or the like.

  Therefore, when trouble occurs or when a periodic inspection is performed, hydrogen sulfide gas having a low concentration is present in the plant.

  Furthermore, when producing hydrogen sulfide gas, it is necessary to replace the hydrogen sulfide gas production facility and its associated facilities with a nitrogen gas atmosphere in advance prior to start-up. Therefore, at the point in time when hydrogen sulfide gas is generated (manufactured) immediately after the operation is started, the concentration of the hydrogen sulfide gas is low, and it is necessary to take measures such as adjusting the flow rate even in a processing plant that uses hydrogen sulfide gas. It is said that.

  These low-concentration hydrogen sulfide gases usually become so-called waste hydrogen sulfide gas and become a loss. Since these waste hydrogen sulfide gases are extremely toxic and cannot be released into the atmosphere as they are, they are treated with flare equipment (equipment that lowers toxicity by burning) or abatement equipment using caustic soda, etc. It is necessary to discharge after that.

  However, in the case of processing with a flare facility, the hydrogen sulfide gas becomes SOx gas, which slightly affects the environment. On the other hand, when detoxifying with a detoxification facility, a neutralizing agent such as caustic soda is required, and the neutralizing agent also needs to be considered as an operating cost, which reduces the efficiency of the operation.

  Therefore, a method for recovering and effectively using these low-concentration hydrogen sulfide gases is required.

  For example, Patent Document 1 discloses that hydrogen sulfide gas is used as caustic soda as a method of recovering excess hydrogen sulfide gas discharged from a sulfidation reaction tank in a sulfidation (nickel recovery) process for producing MS by treating nickel oxide ore. There has been proposed a method in which the sulfur content is used for the sulfurization reaction by returning the liquid to the process through a liquid absorbed in the form (form of sodium hydrosulfide, sodium sulfide, etc.).

  Patent Document 2 discloses that hydrogen sulfide gas volatilized during the dehydration step is absorbed by an organic amide solvent outside the system in which the dehydration step is performed and recovered, and the recovered hydrogen sulfide is a raw material for the alkali metal sulfide. A method for reusing the polymerization reaction is disclosed.

  However, these methods are not methods for recovering hydrogen sulfide as a gas, and also require a recovery solvent such as caustic soda and organic amide.

  Furthermore, Patent Document 3 discloses a method for producing a sulfide containing nickel and cobalt by introducing a sulfuric acid aqueous solution containing nickel and cobalt and supplying a sulfurizing gas containing hydrogen sulfide in the gas phase. A method for maintaining a high yield of nickel and cobalt when the concentration of hydrogen sulfide gas in the sulfide gas supplied into the reaction vessel is reduced from 95 to 100% by volume used in the steady state of operation to a concentration lower than that. Is published. Specifically, when the hydrogen sulfide gas concentration is 85 to 90% by volume, the amount of nickel and cobalt introduced into the reaction vessel is 30 to 35% by mass relative to the amount charged in a steady state, and hydrogen gas When the concentration exceeds 90% by volume, the amount of nickel and cobalt introduced into the reaction vessel is reduced to 55 to 60% by mass.

  Although this method makes it possible to effectively use hydrogen sulfide gas having a concentration lower than that in a steady state, the hydrogen sulfide gas production plant is replaced with nitrogen, for example, the hydrogen sulfide gas concentration is reduced. It is not possible to cope with the case where the capacity drops below 85% by volume.

JP 2010-126778 A Japanese Patent Application Laid-Open No. 09-286861 JP 2009-173983 A

  The present invention has been proposed in view of such circumstances, and efficiently recovers low-concentration hydrogen sulfide gas generated at the time of periodic inspection of a hydrogen sulfide gas production plant, when trouble occurs, or at the beginning of startup. A hydrogen sulfide gas production plant system capable of effectively supplying hydrogen sulfide gas by appropriately controlling supply to a plant (processing plant) that uses hydrogen sulfide gas, and the hydrogen sulfide gas production plant system It is to provide a method for recovering and using hydrogen sulfide gas.

  A hydrogen sulfide gas production plant system according to the present invention includes at least a reaction facility for generating hydrogen sulfide gas from sulfur and hydrogen gas, a plurality of cooling facilities for cooling the generated hydrogen sulfide gas, and the hydrogen sulfide gas. A hydrogen sulfide gas production plant system having a plurality of hydrogen sulfide gas production plants equipped with a sulfur recovery facility for recovering sulfur contained therein, wherein the hydrogen sulfide gas production plant of each system is the above-described sulfur recovery facility. The hydrogen sulfide gas after the sulfur is recovered is branched at a first supply pipe for supplying the hydrogen sulfide gas to a treatment plant that uses the hydrogen sulfide gas, and at a predetermined location in the first supply pipe, A second supply pipe for supplying hydrogen sulfide gas to the processing plant, and the first supply pipe includes the sulfur cycle rather than the predetermined branch point. A concentration meter for measuring the hydrogen sulfide gas concentration is provided on the facility side, and the first supply pipe and the second supply pipe are provided with the supply pipe closer to the processing plant than the predetermined branch point. An ON / OFF valve for turning on / off the supply of hydrogen sulfide gas to the processing plant is provided, and between the predetermined branch point and the ON / OFF valve provided in the second supply pipe. A control valve is provided.

  The method for recovering and using hydrogen sulfide gas according to the present invention includes at least a reaction facility for generating hydrogen sulfide gas from sulfur and hydrogen gas, a plurality of cooling facilities for cooling the generated hydrogen sulfide gas, and the hydrogen sulfide. A method for recovering and using hydrogen sulfide gas in a hydrogen sulfide gas production plant system having a plurality of hydrogen sulfide gas production plants equipped with a sulfur recovery facility for recovering sulfur contained in the gas, wherein the hydrogen sulfide gas of each system The manufacturing plant of the first supply pipe for supplying the hydrogen sulfide gas after the sulfur is recovered by the sulfur recovery facility to the processing plant using the hydrogen sulfide gas, and a predetermined value in the first supply pipe A second supply pipe that branches at a location and supplies hydrogen sulfide gas from the sulfur recovery facility to the treatment plant, and the first supply pipe includes: A concentration meter for measuring the hydrogen sulfide gas concentration is provided closer to the sulfur recovery facility than the predetermined branch point, and the first supply pipe and the second supply pipe are more than the predetermined branch point. An ON / OFF valve for turning ON / OFF the supply of hydrogen sulfide gas to the processing plant via the supply pipe is provided on the processing plant side, and is provided at the predetermined branch point and the second supply pipe. A control valve is provided between the above-mentioned ON / OFF valves, and when a hydrogen sulfide gas having a lower concentration than normal is generated when the operation of any of the plurality of manufacturing plants is stopped, the operation is started. In the production plant that has stopped, the low-concentration hydrogen sulfide gas is recovered through the second supply pipe and supplied to the processing plant while adjusting the flow rate with the control valve. In the production plant the other strains, the hydrogen sulfide gas produced by increasing the production load through the first supply pipe and supplying to the processing plant.

  ADVANTAGE OF THE INVENTION According to this invention, the hydrogen sulfide gas with the low density | concentration which generate | occur | produces at the time of the periodic check of a hydrogen sulfide gas manufacturing plant, trouble generation | occurrence | production, or the start-up can be efficiently collect | recovered, and the plant using hydrogen sulfide gas By appropriately controlling the supply to the (processing plant), the hydrogen sulfide gas can be supplied effectively.

It is a schematic block diagram which shows an example of a structure of a hydrogen sulfide gas manufacturing plant system. It is a control flow diagram which collects low concentration hydrogen sulfide gas generated at the time of periodic inspection, plant start-up, etc., and supplies it to a treatment plant such as a sulfidation treatment plant. It is a schematic block diagram which shows the structure of the conventional hydrogen sulfide gas manufacturing plant. It is a schematic block diagram which shows the structure of the conventional hydrogen sulfide gas manufacturing plant.

Hereinafter, the hydrogen sulfide gas production plant system and the method for recovering and using hydrogen sulfide gas according to the present invention will be described in detail in the following order. Note that the present invention is not limited to the following embodiments, and various modifications can be made without departing from the gist of the present invention.
1. 1. Outline of the present invention 2. Hydrogen sulfide gas production plant system How to recover and use hydrogen sulfide gas 4. Example

[1. Outline of the present invention]
A hydrogen sulfide gas production plant system according to the present invention includes at least a reaction facility for generating hydrogen sulfide gas from sulfur and hydrogen gas, a plurality of cooling facilities for cooling the generated hydrogen sulfide gas, and hydrogen sulfide gas. A hydrogen sulfide gas production plant (hereinafter also simply referred to as “production plant”) having a sulfur recovery facility for recovering sulfur.

  In each production plant, the hydrogen sulfide gas generated in the reaction facility is cooled in the cooling facility, and the sulfur is recovered and removed in the sulfur recovery facility. Supplied to the processing plant to be used (hereinafter also simply referred to as “processing plant”).

  In the present invention, the first supply pipe for supplying the hydrogen sulfide gas after the sulfur is recovered by the sulfur recovery facility to the processing plant using the hydrogen sulfide gas in the manufacturing plant of each system, and the first And a second supply pipe that branches at a predetermined location in the supply pipe and supplies hydrogen sulfide gas from the sulfur recovery facility to the treatment plant.

  And the 1st supply piping is provided with the concentration meter which measures a hydrogen sulfide gas density | concentration in the sulfur recovery equipment side rather than the predetermined branch location. Each of the first supply pipe and the second supply pipe has an ON / OFF valve for turning ON / OFF the supply of hydrogen sulfide gas to the supply pipe closer to the processing plant than the predetermined branch point. Is provided.

  Here, in a hydrogen sulfide gas production plant, when a predetermined periodic inspection, sudden trouble occurs, or when the plant is started up, the hydrogen sulfide gas production plant is separated from the processing plant, and then the hydrogen sulfide gas production plant The inside is replaced with nitrogen gas or the like. When the production plant is stopped at the time of periodic inspection or when trouble occurs, the hydrogen sulfide gas generated before the stop remains in the interior, and the concentration of the hydrogen sulfide gas decreases due to the ventilation of nitrogen gas. Further, even at the time of starting up the plant, in the initial stage, it mixes with the nitrogen gas ventilated inside, and low concentration hydrogen sulfide gas is generated.

  Conventionally, hydrogen sulfide gas having such a low concentration has not been effectively used, and has been a loss in the production of hydrogen sulfide gas as waste hydrogen sulfide gas. And since this low concentration hydrogen sulfide gas cannot be released into the atmosphere as it is, it has been treated using flare equipment, abatement equipment, etc., but there is a considerable impact on the environment, and caustic soda, etc. It was necessary to use a neutralizing agent separately.

  On the other hand, according to the hydrogen sulfide gas production plant system and the method for recovering and using hydrogen sulfide gas using the plant system according to the present invention, the low-concentration hydrogen sulfide gas generated at the time of periodic inspection or the start-up of the plant Can be efficiently recovered and effectively supplied to a processing plant using hydrogen sulfide gas. And since it can be used effectively in this way, it can effectively reduce the burden on the environment without requiring treatment using conventional flare equipment and abatement equipment, and it does not require a neutralizing agent such as caustic soda. This is also advantageous.

  In addition, as a processing plant which uses hydrogen sulfide gas, the dezincification process plant used in the dezincification process in the hydrometallurgy method of nickel oxide ore, the sulfidation process plant used in a sulfidation process, etc. are mentioned, for example. .

  The nickel oxide ore wet smelting method is a hydrometallurgical method of recovering nickel and cobalt from a nickel oxide ore slurry using, for example, a high-temperature high-pressure leaching method (HPAL method). Specifically, this nickel oxide ore hydrometallurgical process consists of a leaching step of adding sulfuric acid to a nickel oxide ore slurry and leaching under high temperature and high pressure, and separating the residue while washing the leaching slurry in multiple stages to obtain nickel and cobalt. And a solid-liquid separation step for obtaining a leachate containing an impurity element, a neutralization step for adjusting the pH of the leachate to separate a neutralized starch containing an impurity element and obtaining a neutralization final solution containing zinc together with nickel and cobalt, A zinc removal process is performed by blowing hydrogen sulfide gas into the final neutralized solution to form zinc sulfide to separate and obtaining a nickel recovery mother liquor containing nickel and cobalt, and nickel sulfide by blowing hydrogen sulfide gas into the nickel recovery mother liquor. And a sulfidation step of forming a mixed sulfide containing cobalt.

  In the dezincification step and the sulfidation step in the nickel oxide ore hydrometallurgy method, metal sulfide is formed by blowing hydrogen sulfide gas into the gas phase of the reaction tank in each plant to cause a sulfidation reaction. Therefore, in contrast to treatment plants that use these hydrogen sulfide gases, low-concentration hydrogen sulfide gases that were conventionally disposed of as waste hydrogen sulfide gas together with hydrogen sulfide gas that was normally produced from the hydrogen sulfide gas production plant By efficiently recovering and supplying the hydrogen sulfide gas, the hydrogen sulfide gas produced at the hydrogen sulfide gas production plant can be supplied without loss. Moreover, in the processing plant which uses each hydrogen sulfide gas, it becomes possible to reduce the use cost of hydrogen sulfide gas, and can perform efficient hydrometallurgical operation.

  Hereinafter, specific embodiments relating to a hydrogen sulfide gas production plant system and a method for recovering and using hydrogen sulfide gas according to the present invention will be described more specifically with reference to the drawings. Note that the hydrogen sulfide gas production plant according to the present embodiment is an improvement of the hydrogen sulfide gas production plant 60 shown in FIG. 4 described above, and a part of the description is omitted.

[2. Hydrogen sulfide gas production plant system]
FIG. 1 is a schematic diagram illustrating an example of a configuration of a hydrogen sulfide gas production plant system. A hydrogen sulfide gas production plant system 1 shown in FIG. 1 has a plurality of hydrogen sulfide production plants described below. As will be described in detail later, the manufacturing plants of the respective systems are connected to the supply piping for supplying the generated hydrogen sulfide gas, and the hydrogen sulfide gas generated in each manufacturing plant is connected to the same processing plant. To supply.

  In addition, in the hydrogen sulfide gas production plant system 1 shown in FIG. 1, a hydrogen sulfide gas production plant (manufacturing plant 10 </ b> A, production plant 10 </ b> B) is exemplified as an example, but is not limited to two systems. Alternatively, it may have a manufacturing plant of a plurality of systems of three or more systems.

  Hereinafter, the manufacturing plant which comprises the hydrogen sulfide gas manufacturing plant system 1 is demonstrated concretely. In addition, since the structure of each manufacturing plant is the same, about the same structure in each manufacturing plant, the same numerical code | symbol is attached | subjected and 10 A of manufacturing plants are demonstrated typically.

<Hydrogen sulfide gas production plant>
The hydrogen sulfide gas production plant 10A includes a reaction facility 11A for generating hydrogen sulfide gas, a plurality of cooling facilities 12A for cooling the generated hydrogen sulfide gas, and hydrogen sulfide from which sulfur in the hydrogen sulfide gas is recovered and sulfur is removed. And a sulfur recovery facility 13A for supplying gas. Further, the hydrogen sulfide gas production plant 10A includes a first supply pipe 14A for supplying the hydrogen sulfide gas after the sulfur is recovered by the sulfur recovery facility 13A to the processing plant X using the hydrogen sulfide gas, And a second supply pipe 16A for branching at a predetermined location 15A in the supply pipe 14A and supplying the hydrogen sulfide gas from the sulfur recovery facility 13A to the processing plant X.

  In addition, the hydrogen sulfide gas production plant 10 </ b> A stores the sulfur recovered and removed by the sulfur recovery facility 13, and supplies a blowdown facility 17 </ b> A and a reaction facility 11 </ b> A that supplies the sulfur to a plant (sulfur processing plant). And a sulfur cooling facility 18A for cooling the sulfur in order to adjust the heat balance.

(Reaction equipment)
For example, the reaction equipment 11A includes a reactor 19A, a quench tower 20A, and a heater 21A. The reaction equipment 11A causes a hydrogen sulfide gas generation reaction by the supplied sulfur and hydrogen gas, and generates hydrogen sulfide gas.

  More specifically, in the reaction equipment 11A, molten sulfur is stored in the reactor 19A, and hydrogen gas is supplied from the lower part thereof, so that the reaction proceeds while the upward flow of hydrogen gas passes through the molten sulfur. Hydrogen sulfide gas is generated. Most of the hydrogen sulfide gas generated here is hydrogen sulfide, but part of it contains sulfur vapor that is entrained when the hydrogen gas passes through the reactor 19A.

  Further, the reaction facility 11A is operated under relatively high temperature and high pressure conditions of a temperature of about 470 ° C. and a pressure of about 800 kPaG, and the generated hydrogen sulfide gas is also at a high temperature and a high pressure. In addition, since the hydrogen sulfide gas generated in the reaction facility 11A exchanges heat with the supplied sulfur, the temperature is about 150 ° C. when passing through the quench tower 20A.

  Here, as described above, hydrogen gas for reacting with the molten sulfur is supplied from the lower part of the reactor 19A. However, at the time of periodic inspection, trouble occurrence, or plant startup, the lower part of the reactor 19A. Is supplied with nitrogen gas. The supplied nitrogen gas passes through the reaction equipment 11A, shifts to the respective equipment such as the cooling equipment 12A and the sulfur recovery equipment 13A, and replaces the inside of the manufacturing plant 10A.

  At this time, at the time of periodic inspection or trouble occurrence, hydrogen sulfide gas is generated until immediately before the stop of the production plant, so that hydrogen sulfide gas remains in the inside. For this reason, when nitrogen gas is supplied to the manufacturing plant 10A, the remaining hydrogen sulfide gas and nitrogen gas are mixed to produce hydrogen sulfide gas having a low concentration. Further, since hydrogen sulfide gas is gradually generated in the manufacturing plant 10A filled with nitrogen gas at the time of starting the plant, in the initial stage, low concentration hydrogen sulfide gas is generated inside the manufacturing plant 10A. Will exist.

  In the hydrogen sulfide gas production plant system 1 according to the present embodiment, the low-concentration hydrogen sulfide gas generated in this way can be efficiently recovered and effectively supplied to the processing plant X. Details will be described later.

(Cooling equipment)
The cooling facility 12A collects hydrogen sulfide gas generated in the reaction facility 11A. The cooling temperature of the hydrogen sulfide gas in the cooling facility 12A is not particularly limited, but is preferably lower in order to reduce the sulfur content in the hydrogen sulfide gas. Specifically, since normal (cooling) water is used, it is cooled to about 50 ° C.

The hydrogen sulfide gas production plant 10A includes a plurality of cooling facilities 12A (cooling facilities 12A ₁ , 12A ₂ ,..., 12A _n ). In the cooling facility 12A, a part of the sulfur contained in the recovered hydrogen sulfide gas is solidified and fixed inside the facility (heat transfer surface). Therefore, by providing a plurality of cooling facilities 12A, it is possible to alternately use them, and to prevent a decrease in operation efficiency due to a decrease in cooling capacity. The hydrogen sulfide gas production plant 10 shown in FIG. 1 is an example having two systems of cooling facilities 12A ₁ and 12A ₂ .

Specifically, in the cooling facilities 12A ₁ and 12A ₂ , for example, a jacket is provided around the lower portion thereof, and the fixed sulfur can be melted by heating with steam. For example, when the sulfur is fixed to the cooling system 12A ₁ switches to cooling equipment 12A ₂ stop using the cooling equipment 12A _1. In the cooling equipment 12A ₁ was stopped using sulfur which is fixed by steam is being melted recovered.

Here, since the cooling facilities 12A ₁ and 12A ₂ have cooled hydrogen sulfide gas until just before the facilities whose use has been temporarily stopped, the high-pressure and high-concentration hydrogen sulfide gas is held in the cooling facilities 12A ₁ and 12A _2. Yes. For this reason, in the melt recovery processing of sulfur fixed inside, it is necessary to discharge the hydrogen sulfide gas in the cooling facilities 12A ₁ and 12A ₂ for melting and recovering the sulfur and reduce the internal pressure. In the hydrogen sulfide gas production plant 10A, the hydrogen sulfide gas discharged at this time is generated from the cooling facilities 12A ₁ and 12A ₂ as waste hydrogen sulfide gas.

As a discharge mode of the waste hydrogen sulfide gas from the hydrogen sulfide gas production plant 10A, for example, together with sulfur melted and recovered in the cooling facilities 12A ₁ and 12A ₂ , the waste hydrogen sulfide gas is discharged to the blow-down facility 17A described later. The pressure is released and discharged from the outlet provided in the blowdown equipment 17A. Or, the waste hydrogen sulfide gas generated in the cooling system _12A 1, 12A _2, may be discharged directly from the outlet provided in the cooling equipment _12A 1, 12A _2.

In addition, when waste hydrogen sulfide gas is discharged from the discharge ports provided in the blowdown facility 17A and the cooling facilities 12A ₁ and 12A ₂ , the discharge ports of those facilities are connected to a predetermined processing plant that uses the hydrogen sulfide gas. Piping can be provided. Thereby, waste hydrogen sulfide gas generated through the piping can be effectively recovered and supplied to a predetermined processing plant.

(Sulfur recovery equipment)
The sulfur recovery facility (knockout facility) 13A recovers and removes sulfur in the hydrogen sulfide gas cooled by the cooling facilities 12A ₁ and 12A ₂ . Then, the sulfur recovery facility 13A supplies the hydrogen sulfide gas from which sulfur has been removed to the processing plant X that uses the hydrogen sulfide gas.

  As described above, the hydrogen sulfide gas generated in the reaction facility 11A partially contains sulfur vapor. In the sulfur recovery facility 13A, the sulfur vapor is solidified and deposited on the bottom, and the sulfur is melted and recovered, for example, by heating with steam through a jacket installed in the outer periphery of the lower part. The recovered sulfur is transferred to a blowdown facility 17A described later.

  In addition, as the processing plant X which becomes the supply destination of the hydrogen sulfide gas supplied from the sulfur recovery facility 13A, as described above, a sulfidation process plant, a dezincification process plant, etc. used in the nickel oxide ore wet smelting method, etc. And sulfidation plants.

(First supply piping)
The first supply pipe 14A has one end connected to the sulfur recovery facility 13A and the other end connected to the processing plant X using hydrogen sulfide gas, and the sulfur after the sulfur is recovered by the sulfur recovery facility 13A. Hydrogen gas is supplied to the processing plant X.

  The first supply pipe 14A has a pipe connection point that can branch to a predetermined location 15A, and a second supply pipe 16A described later is connected at the pipe connection point.

  Further, the first supply pipe 14A passes through the first supply pipe 14A on the upstream side of the predetermined portion 15A serving as a pipe connection point with the second supply pipe 16A, that is, on the sulfur recovery facility 13A side. A concentration meter 22A for measuring the concentration of the hydrogen sulfide gas supplied is provided. In addition, the first supply pipe 14A is turned ON / OFF to supply hydrogen sulfide gas to the processing plant via the first supply pipe 14A on the downstream side of the predetermined portion 15A, that is, on the processing plant X side. An ON / OFF valve 23A for performing OFF control is provided.

  In the hydrogen sulfide gas production plant system 1, the first supply pipe 14A of the production plant 10A and the first supply pipe 14B of the production plant 10B are connected at predetermined locations, and the respective production plants 10A, 10B. The hydrogen sulfide gas produced therein is mixed through the first supply pipes 14A and 14B and supplied to the processing plant X.

  The first supply pipes 14A and 14B are connected to the processing plant X via continuous supply pipes (hereinafter referred to as “supply pipes 14C” for convenience), and are manufactured at the respective production plants 10A and 10B. The hydrogen sulfide gas mixed through the first supply pipes 14A and 14B is supplied to the processing plant X through the supply pipe 14C. The supply pipe 14C is provided with a control valve 24 for controlling the supply amount of hydrogen sulfide gas to the processing plant X, and the flow rate of hydrogen sulfide gas is measured closer to the processing plant X than the control valve 24. A flow meter 25 is provided. In the supply pipe 14 </ b> C, the supply amount of hydrogen sulfide gas to the processing plant can be controlled by adjusting the control valve 24 according to the flow rate measured by the flow meter 25.

(Second supply pipe)
As described above, one end of the second supply pipe 16A is connected to a predetermined location 15A that is a pipe connection point in the first supply pipe 14A. The other end is connected to a processing plant X that uses hydrogen sulfide gas, and the hydrogen sulfide gas from which sulfur has been recovered by the sulfur recovery facility 13A is supplied to the processing plant X.

  Further, the second supply pipe 16A is provided with ON / OFF control of the supply of hydrogen sulfide gas to the processing plant X via the second supply pipe 16A immediately after the connection point with the first supply pipe 14A. An ON / OFF valve 26A for performing is provided.

  The second supply pipe 16A is a supply pipe for so-called low-concentration hydrogen sulfide gas, which mainly collects low-concentration hydrogen sulfide gas generated at the time of periodic inspection or plant startup and supplies it to the processing plant X. is there.

  The processing plant X to which the first supply pipe 14A is connected and the processing plant X to which the second supply pipe 16A is connected are the same processing plant. Then, by recovering low concentration hydrogen sulfide gas generated at the time of periodic inspection or start-up through the second supply pipe 16A, the low concentration hydrogen sulfide gas which has been conventionally discarded as waste hydrogen sulfide gas is recovered. The hydrogen sulfide gas can be effectively supplied to the processing plant X. Thereby, it can prevent that the processing efficiency in the processing plant X falls by supply of the hydrogen sulfide gas to the processing plant X stagnating. Details will be described later.

  In the hydrogen sulfide gas production plant system 1, the second supply pipe 16A of the production plant 10A and the second supply pipe 16B of the production plant 10B are connected at predetermined locations, and the respective production plants 10A, 10B. The low-concentration hydrogen sulfide gas generated inside is supplied to the same processing plant X.

  When the second supply pipe 16A of the manufacturing plant 10A and the second supply pipe 16B of the manufacturing plant 10B are connected, they are connected via a supply pipe (hereinafter referred to as “supply pipe 16C” for convenience). It is connected to the processing plant X. The supply pipe 16C is provided with a pressure gauge 27 for measuring the pressure of the hydrogen sulfide gas supplied to the processing plant X and a flow meter 28 for measuring the flow rate of the hydrogen sulfide gas. Further, a control valve 29 for controlling the supply of hydrogen sulfide gas to the processing plant X is provided in the supply pipe 16C.

  As described above, the supply pipe 16C is provided with the pressure gauge 27, the flow meter 28, and the control valve 29, so that the control valve 29 is controlled according to the pressure and flow rate of the hydrogen sulfide gas. Under the supply control, it is possible to supply a low concentration hydrogen sulfide gas to the processing plant X.

  In addition, at least one ON / OFF valve 30 is provided in the supply pipe 16C, and it is possible to isolate low-concentration hydrogen sulfide gas between the hydrogen sulfide gas production plant 10 and the processing plant X in an emergency. I have to.

  The second supply pipe 16A may be provided with a control valve between the first supply pipe 14A and the ON / OFF valve 26A. As a result, not only the produced hydrogen sulfide gas is transferred via the first supply pipe but also the control valve provided in the second supply pipe is adjusted in the production plant that is normally operated. Thus, a part of the produced hydrogen sulfide gas can be recovered also in the second supply pipe.

  For example, the low concentration hydrogen sulfide gas generated in the manufacturing plant 10A is collected through the second supply pipe 16A, and part of the high concentration hydrogen sulfide gas manufactured in the manufacturing plant 10B that is normally operated. Is adjusted by the control valve and recovered through the second supply pipe 16B. Then, by mixing the low concentration hydrogen sulfide gas in the manufacturing plant 10A and the high concentration hydrogen sulfide gas in the manufacturing plant 10B, it is possible to supply the hydrogen sulfide gas whose concentration is finely adjusted.

(Blowdown equipment)
The blowdown facility 17A recovers sulfur removed from the hydrogen sulfide gas by the sulfur recovery facility 13A. In addition, the blowdown facility 17A collects sulfur that has adhered to the cooling facilities 12A ₁ and 12A ₂ . Then, the blow-down facility 17A supplies the recovered sulfur to, for example, a sulfur treatment plant by the supply pump 31A. Alternatively, the recovered sulfur may be recycled as a sulfur source to be supplied to the reaction equipment 11A again.

Further, the blow-down facility 17A may be provided with a discharge port for discharging waste hydrogen sulfide gas generated in the cooling facilities 12A ₁ and 12A ₂ and discharged to the blow-down facility 17A to the outside of the system. And piping may be couple | bonded with the discharge port, and waste hydrogen sulfide gas may be supplied to a predetermined | prescribed processing plant via the piping. Thereby, waste hydrogen sulfide gas generated in the cooling facilities 12A ₁ and 12A ₂ can also be effectively used.

(Sulfur cooling equipment)
The sulfur cooling facility 18A cools sulfur from about 470 ° C. to about 150 ° C. in order to adjust the heat balance in the reaction facility 11A. Further, the sulfur cooling facility 18A supplies the cooled sulfur to, for example, the blowdown facility 17A, and supplies it to the sulfur treatment plant together with the sulfur recovered from the cooling facilities 12A ₁ , 12A ₂ and the sulfur recovery facility 13A. Alternatively, the cooled sulfur may be recycled as a sulfur source to be supplied again to the reaction facility 11A by the circulation pump 32A.

[3. How to recover and use hydrogen sulfide gas]
Next, a method for recovering and using the hydrogen sulfide gas generated in the hydrogen sulfide gas production plant system 1 described above, particularly the low-concentration hydrogen sulfide gas generated at the time of periodic inspection or start-up will be described.

<Overview of how to recover and use hydrogen sulfide gas>
As described above, each of the hydrogen sulfide gas production plants 10A and 10B constituting the hydrogen sulfide gas production plant system 1 includes the first supply pipes 14A and 14B that supply the processing plant X using the hydrogen sulfide gas, Second supply pipes 16A and 16B branched from predetermined locations 15A and 15B of the first supply pipes 14A and 14B are provided. The first supply pipes 14A and 14B are provided with densitometers 22A and 22B on the upstream side of the branch points 15A and 15B, and the first supply pipes 14A and 14B are connected to the second supply pipes 14A and 14B. The supply pipes 16A and 16B are provided with ON / OFF valves 23A, 23B, 26A and 26B for controlling the supply of hydrogen sulfide gas through the pipes.

  Here, in the hydrogen sulfide gas production plant system 1, when a predetermined periodic inspection, sudden trouble occurs, or when the plant is started up, the hydrogen sulfide gas production plant is stopped and the inside of the production plant is replaced with nitrogen gas or the like. Processing is performed. Then, since the hydrogen sulfide gas that has just been generated remains in the manufacturing plant, the hydrogen sulfide gas concentration that is mixed with the ventilated nitrogen gas and has a low concentration exists. Further, even at the time of starting up the plant, in the initial stage, it mixes with the nitrogen gas ventilated inside, and low concentration hydrogen sulfide gas is generated.

  When the low-concentration hydrogen sulfide gas generated at the time of regular inspection or startup is supplied to the processing plant X through the supply pipe as usual, the processing using the hydrogen sulfide gas in the processing plant X is performed. It may become unstable and prevent effective processing. In addition, in a hydrogen sulfide gas production plant system having a plurality of production plants, there is a possibility that the operation on the side of the production plant that is normally operated becomes unstable.

  For this reason, in the past, such low-concentration hydrogen sulfide gas was disposed of as waste hydrogen sulfide gas. Naturally, however, the exhaust gas was lost to hydrogen sulfide gas production, and labor and cost were required for the detoxification treatment. Was. Furthermore, in the hydrogen sulfide gas production plant system, the operation of the processing plant X to which hydrogen sulfide gas is supplied must be operated with the maximum load of the production plant capable of normal operation not to be inefficient. It was good.

  Therefore, in the present embodiment, when any one of the production plants constituting the hydrogen sulfide gas production plant system 1 is stopped based on periodic inspection or the like, or when the plant is started up, nitrogen gas is used. When low-concentration hydrogen sulfide gas is generated by the replacement process, the low-concentration hydrogen sulfide gas is recovered through the second supply pipe in the production plant where the operation is stopped.

  Then, a low-concentration hydrogen sulfide gas recovered through the second supply pipe and a hydrogen sulfide gas manufactured on the side of the manufacturing plant that has been operating normally and recovered through the first supply pipe are predetermined. To the same processing plant X. At this time, the production load (operation load) of the production plant on which the operation is normally continued is slightly increased to produce and supply a larger amount of hydrogen sulfide gas than usual.

  “Production load (operation load)” refers to the production throughput of the hydrogen sulfide gas production plant, and “increasing production load” means producing more hydrogen sulfide gas than normal (steady). To do.

  Here, as disclosed in Patent Document 3, for example, in the sulfidation process in the sulfiding step in the hydrometallurgy method of nickel oxide ore, if the supplied hydrogen sulfide gas concentration is 85% by volume or more, The amount of nickel and cobalt to be charged is reduced to 30 to 35% by mass ratio with respect to the amount charged in a steady state, thereby efficiently producing a sulfurization reaction and high yields of nickel and cobalt sulfides. I know you can get

  Therefore, in the hydrogen sulfide gas production plant system 1, the low concentration hydrogen sulfide gas recovered and supplied from the production plant that has been stopped from operation and the normal concentration hydrogen sulfide gas supplied from the production plant that is operating normally are used. By mixing, the weighted average value of the concentration is, for example, 85% by volume or more. Thereby, hydrogen sulfide gas including low-concentration hydrogen sulfide gas can be effectively supplied without reducing the operation efficiency in the treatment plant X.

  Note that the weighted average value of the concentration of hydrogen sulfide gas supplied from the hydrogen sulfide gas production plant system 1 is not limited to 85% by volume or more, and is appropriately determined according to the type of reaction in the processing plant X to be supplied. can do. And according to the weighted average value of the density | concentration of the hydrogen sulfide gas which should be supplied, the increase amount of the load with respect to the manufacturing plant which is operating normally can be determined.

<Control flow for collection and usage>
FIG. 2 is a control flow for recovering low-concentration hydrogen sulfide gas generated during periodic inspections, plant startup, and the like and supplying the hydrogen sulfide gas to a treatment plant X such as a sulfidation treatment plant. Hereinafter, a method for recovering and using hydrogen sulfide gas including low-concentration hydrogen sulfide gas will be described more specifically based on FIG.

  In the following description, in the hydrogen sulfide gas production plant system 1, when the operation of the production plant 10A is stopped by periodic inspection or the like, low concentration hydrogen sulfide gas is generated inside the production plant 10A. Will be described as an example.

  First, when hydrogen sulfide gas is produced in the production plant 10A during normal operation of the production plant 10A (step S11a), the hydrogen sulfide gas obtained from the sulfur recovery facility 13A is treated through the first supply pipe 14A. Is supplied to X (step S12a).

  On the other hand, also in the manufacturing plant 10B which comprises the hydrogen sulfide gas manufacturing plant system 1 with the manufacturing plant 10A, if hydrogen sulfide gas is manufactured in the manufacturing plant 10B (step S11b), the hydrogen sulfide gas obtained from the sulfur recovery equipment 13B Is supplied to the same processing plant X via the first supply pipe 14B (step S12b).

  Thus, during normal operation, hydrogen sulfide gas having a normal concentration produced in the production plant 10A and the production plant 10B is supplied to the same processing plant X via the first supply pipes 14A and 14B, respectively. Then, it is used in the treatment plant X for sulfidation treatment or the like.

  Therefore, during normal operation, the operation load on each of the manufacturing plants 10A and 10B is almost equal.

  Next, for example, when periodic equipment inspection is performed in the manufacturing plant 10A or when a sudden trouble occurs, in step S13, the operation of the manufacturing plant 10A is stopped, and nitrogen gas is introduced into the manufacturing plant 10A. To perform replacement processing. When the replacement process is performed, the hydrogen sulfide gas generated immediately before the operation is stopped and remaining in the manufacturing plant 10A is diluted with nitrogen gas, and a hydrogen sulfide gas having a concentration lower than a predetermined concentration is generated in the manufacturing plant 10A. Arise.

  Therefore, when a replacement operation with nitrogen gas is performed, first, in step S14, the concentration of the hydrogen sulfide gas obtained from the sulfur recovery facility 13A is measured by the densitometer 22A.

  Next, in step S15, it is determined whether or not the measured concentration of hydrogen sulfide gas is equal to or higher than a predetermined concentration. That is, it is determined whether or not a low concentration hydrogen sulfide gas is flowing.

  In step S15, when it is determined that the concentration of the hydrogen sulfide gas is equal to or higher than the predetermined concentration (in the case of Yes), the manufacturing plant 10A returns to step S12a to supply the hydrogen sulfide gas to the first supply pipe 14A. And is supplied to the processing plant X. In the production plant 10B, the process returns to step S12b, and the produced hydrogen sulfide gas is recovered and supplied to the processing plant X through the first supply pipe 14B as usual.

  On the other hand, if it is determined in step S15 that the concentration of the hydrogen sulfide gas is less than the predetermined concentration (in the case of No), a low concentration hydrogen sulfide gas is generated in the manufacturing plant 10A by replacement with nitrogen gas. Therefore, the process proceeds to step S16a in the manufacturing plant 10A, and proceeds to step S16b in the manufacturing plant 10B.

  In step S16a, in the manufacturing plant 10A, the ON / OFF valve 23A provided in the first supply pipe 14A is closed, and the ON / OFF valve 26A provided in the second supply pipe 16A is opened.

  Subsequently, the process proceeds to step S17a, where the low concentration hydrogen sulfide gas generated in the manufacturing plant 10A is recovered by the second supply pipe 16A, and then the recovered low concentration hydrogen sulfide gas is supplied to the second supply pipe 16A. It supplies to the processing plant X via the piping 16A.

  On the other hand, in the production plant 10B, the production load of the production plant 10B is slightly increased in step S16b. As a result, a larger amount of hydrogen sulfide gas is produced than during normal operation.

  Then, the process proceeds to step S18b, and the hydrogen sulfide gas manufactured with a slightly increased manufacturing load is supplied to the processing plant X via the first supply pipe 14B. The degree of increase in production load at this time can be determined based on the weighted average value of the concentration of hydrogen sulfide gas supplied from the production plant 10A and the production plant 10B.

  Thus, in the manufacturing plant 10A, hydrogen sulfide gas with a low concentration is supplied to the processing plant X via the second supply pipe 16A, and the manufacturing plant 10B produces a larger amount of hydrogen sulfide gas than in normal operation. To the processing plant X via the first supply pipe 14B.

  At this time, in step S19, it supplies so that the weighted average value of the density | concentration of the hydrogen sulfide gas supplied with respect to the processing plant X from the manufacturing plant 10A and the manufacturing plant 10B may be 85 volume% or more. This weighted average value is calculated from the hydrogen sulfide gas concentration and the hydrogen sulfide gas amount based on the low concentration hydrogen sulfide gas from the manufacturing plant 10A and the normal concentration hydrogen sulfide gas from the manufacturing plant 10B. The amount of nitrogen gas supplied for replacement can be adjusted. Note that the amount of hydrogen sulfide gas and the like are determined based on the measurement value of the flow meter 28 that measures the flow rate of the hydrogen sulfide gas supplied from the supply pipe 16C in the hydrogen sulfide gas production plant system 1 shown in FIG. Can do.

  As described above, when low-concentration hydrogen sulfide gas is generated in the manufacturing plant 10A, the low-concentration hydrogen sulfide gas is recovered by the second supply pipe 16A and supplied to the processing plant X. On the other hand, a large amount of hydrogen sulfide gas is manufactured and supplied to the processing plant X after slightly increasing the manufacturing load in the normal operation manufacturing plant 10B in which the operation is not stopped.

  By performing such an operation and controlling the hydrogen sulfide gas having a weighted average value of 85% by volume or more to be supplied to the processing plant X, the low-concentration hydrogen sulfide gas that has been conventionally discarded can be effectively used. And can be effectively supplied to the processing plant X. In addition, since there is no hydrogen sulfide gas to be discarded, there is no production loss, and it is possible to omit the environmental burden associated with the exhaust process, the disposal process, and the associated costs.

  Moreover, also in the processing plant X which is the supply destination of hydrogen sulfide gas, it is possible to prevent the supply efficiency from being extremely reduced at every periodic inspection of the manufacturing plant and the processing efficiency such as the sulfiding treatment from being lowered.

  Now, returning the description to the control flow of FIG. 2, when the periodic inspection or the like for the manufacturing plant 10 </ b> A is completed, the manufacturing plant 10 </ b> A is started up and the operation is resumed in step S <b> 20.

  In the initial stage of startup, a sufficient concentration of hydrogen sulfide gas is not produced. From this, first, in step S21, the concentration of the hydrogen sulfide gas produced in the production plant 10A and obtained from the sulfur recovery facility 13A is measured by the densitometer 22A.

  Next, in step S22, it is determined whether or not the measured concentration of hydrogen sulfide gas is equal to or higher than a predetermined concentration. That is, it is determined whether or not a low-concentration hydrogen sulfide gas is still flowing.

  In this step S22, when it is determined that the concentration of the hydrogen sulfide gas is less than the predetermined concentration (in the case of No), since the hydrogen sulfide gas having a normal concentration is not sufficiently generated, the production plant 10A In step S17a, the low-concentration hydrogen sulfide gas is recovered by the second supply pipe 16A, and is supplied to the processing plant X through the second supply pipe 16A in step S18a. In the manufacturing plant 10B, the process returns to step S18b, and a large amount of hydrogen sulfide gas manufactured under a high load is recovered through the first supply pipe 14B and supplied to the processing plant X.

  At this time, in step S19, the hydrogen sulfide gas concentration and the hydrogen sulfide gas amount are calculated based on the low concentration hydrogen sulfide gas from the manufacturing plant 10A and the normal hydrogen sulfide gas from the manufacturing plant 10B. The amount of hydrogen gas supplied to the reaction equipment 11A of the manufacturing plant 10A is adjusted so that the weighted average value of the hydrogen sulfide concentration is 85 volume% or more.

  On the other hand, if it is determined in step S22 that the concentration of the hydrogen sulfide gas is equal to or higher than the predetermined concentration (in the case of Yes), the process proceeds to step S23a in the manufacturing plant 10A, and the process proceeds to step S23b in the manufacturing plant 10B. move on.

  In step S23a, in the manufacturing plant 10A, the ON / OFF valve 23A provided in the first supply pipe 14A is opened, and the ON / OFF valve 26A provided in the second supply pipe 16A is closed.

  That is, returning to normal operation, the hydrogen sulfide gas obtained from the sulfur recovery facility 13A is supplied to the processing plant X via the first supply pipe 14A (step S12a).

  On the other hand, in the manufacturing plant 10B, in step S23b, the increased manufacturing load is returned to the normal load, and the hydrogen sulfide gas obtained from the sulfur recovery facility 13B is transferred to the processing plant X via the first supply pipe 14B. Supply (step S12b).

  As described above, the hydrogen sulfide gas production plant system 1 can effectively recover low-concentration hydrogen sulfide gas generated during periodic inspections, plant startup, and the like by performing the above-described control. The recovered hydrogen sulfide gas can be effectively supplied to the processing plant X.

[4. Example]
Examples of the present invention will be described below, but the present invention is not limited to the following examples.

Example 1
As Example 1, hydrogen sulfide gas is produced using a hydrogen sulfide gas production plant system 1 consisting of two systems of hydrogen sulfide gas production plants 10A and 10B shown in FIG. 1, and sulfide is obtained in the hydrometallurgy of nickel oxide ore. The operation for supplying hydrogen sulfide gas to the sulfidation process plant X performing the process was performed. Moreover, in this operation, the operation of recovering low-concentration hydrogen sulfide gas generated during periodic inspection of one of the two systems and supplying the recovered low-concentration hydrogen sulfide gas to the sulfidation treatment plant. Went.

  Specifically, as shown in FIG. 1, in the hydrogen sulfide gas production plants 10A and 10B, the first supply piping 14A for supplying the hydrogen sulfide gas obtained from the sulfur recovery facilities 13A and 13B to the sulfurization process plant X, 14B is provided, and second supply pipes 16A and 16B branched at predetermined locations 15A and 15B of the first supply pipes 14A and 14B are provided.

  The first supply pipes 14A and 14B are provided with concentration meters 22A and 22B for measuring the hydrogen sulfide gas concentration upstream of the branch points 15A and 15B. Further, in the first supply pipes 14A and 14B and the second supply pipes 16A and 16B, hydrogen sulfide gas to the sulfidation process plant X via the respective supply pipes is provided downstream of the branch points 15A and 15B. ON / OFF valves 23A, 23B, 26A, and 26B for controlling the supply of the above are provided.

  In continuing the operation, periodic inspections are alternately performed on one of the hydrogen sulfide gas production plants 10A and 10B of the two systems, and at the time of the inspection, the operation of the production plant to be inspected is stopped, Replacement with nitrogen gas was performed. At this time, the low-concentration hydrogen sulfide gas generated in the replacement work with nitrogen gas was recovered through the second supply pipe in the manufacturing plant whose operation was stopped. On the other hand, about the manufacturing plant of the side normally operated at that time, the manufacturing load was slightly increased and a large amount of hydrogen sulfide gas was produced.

  Based on the recovered low-concentration hydrogen sulfide gas and the hydrogen sulfide gas produced at a normally operating production plant, the hydrogen sulfide gas is weighted and averaged from the hydrogen sulfide gas concentration and the amount of hydrogen sulfide gas. The amount of nitrogen gas was adjusted so as to ensure a concentration of 85% by volume.

  In addition, even when the hydrogen sulfide gas production plant was stopped, the hydrogen sulfide gas having a low concentration generated from the hydrogen sulfide gas production plant replaced with nitrogen gas is recovered and operated normally. Together with the hydrogen sulfide gas produced from the production plant, the amount of hydrogen gas was adjusted so that 85% by volume of the hydrogen sulfide gas concentration obtained by weighted averaging from the concentration and the gas amount could be secured.

  The operating pressure conditions in the reaction facilities 11A and 11B of the hydrogen sulfide gas production plants 10A and 10B were 780 kPag as a daily average value, although there were some fluctuations. On the other hand, the pressure condition in the sulfidation treatment plant X to which hydrogen sulfide gas was supplied was 280 kPag, and the pressure condition in the dezincification sulfidation treatment plant was 2 kPag.

  The operation for 6 months was carried out by the hydrogen sulfide gas production plant system 1 configured as described above.

  As a result of the operation, during the operation period of 6 months, a total of 10 times of start-up and shut-down of the production plant accompanying the periodic inspection for the hydrogen sulfide gas production plants 10A and 10B occurred. The low-concentration hydrogen sulfide gas generated at this time becomes 3.1t in total, and can be recovered through the second supply pipes 16A and 16B. The plant X could be supplied.

  At the same time, a low-concentration hydrogen sulfide gas as much as about 3.1 tons can be recovered and supplied, and since there was no production loss, a raw material-type operating material equivalent to producing 3.1 tons of the hydrogen sulfide gas As a result, it was possible to save about 3.0 tons of sulfur and about 0.3 tons of hydrogen gas (methanol). In addition, caustic soda for absorbing and removing hydrogen sulfide gas is no longer required as a waste treatment material used to dispose of the low-concentration hydrogen sulfide gas. . In addition, the conventional process of removing the waste hydrogen sulfide gas into the atmosphere after detoxifying it with the flare facility is no longer necessary, so there was no burden on the environment.

(Comparative Example 1)
In Comparative Example 1, operation was performed using a conventional hydrogen sulfide gas production plant.

  As a result, about 3.1 t of low-concentration hydrogen sulfide gas generated in the cooling facility was discarded as waste hydrogen sulfide gas without being collected by the abatement facility. Then, about 4.3 t of caustic soda for absorbing and detoxifying the hydrogen sulfide gas is required for the treatment by the abatement equipment. Further, in order to make up for the production loss (recovery loss), as compared with Example 1, about 3.0 t of sulfur and about 0.3 t of hydrogen were required as raw material-based operation materials.

  Even when hydrogen sulfide gas is processed in a flare facility, the generated sulfur oxide (SOx) has a possibility of being released to the atmosphere.

  Furthermore, when the hydrogen sulfide gas production plant is shut down, it must be stopped once and then replaced with nitrogen gas. Therefore, in other production plants operating normally, it takes about 10 days (once). It was necessary to stop the supply of hydrogen sulfide gas for about one day per stop). As a result, it is also necessary to stop a series of processes including the leaching process in the hydrometallurgy of nickel oxide ore, and the production and startup of the manufacturing plant has resulted in a significant decrease in production volume of 1000 Ni-t. It was.

  DESCRIPTION OF SYMBOLS 1 Hydrogen sulfide gas manufacturing plant system, 10A, 10B Hydrogen sulfide gas manufacturing plant, 11A, 11B Reaction equipment, 12, 12A, 12B Cooling equipment, 13A, 13B Sulfur recovery equipment, 14A, 14B First supply piping, 15A, 15B Branch point, 16A, 16B second supply pipe, 17A, 17B blowdown equipment, 18A, 18B sulfur cooling equipment, 19A, 19B reactor, 20A, 20B quench tower, 21A, 21B heater, 22A, 22B densitometer, 23A, 23B ON / OFF valve, 24 control valve, 25 pressure gauge, 26A, 26B ON / OFF valve, 27 pressure gauge, 28 flow meter, 29 control valve, 30 ON / OFF valve, 31A, 31B supply pump, 32A, 32B circulation pump

Claims (14)

At least a reaction facility for generating hydrogen sulfide gas with sulfur and hydrogen gas, a plurality of cooling facilities for cooling the generated hydrogen sulfide gas, and a sulfur recovery facility for recovering sulfur contained in the hydrogen sulfide gas. A hydrogen sulfide gas production plant system having a plurality of hydrogen sulfide gas production plants,
Each system of hydrogen sulfide gas production plant is
A first supply pipe for supplying the hydrogen sulfide gas after sulfur is recovered by the sulfur recovery facility to a treatment plant using the hydrogen sulfide gas;
A second supply pipe that branches at a predetermined location in the first supply pipe and supplies hydrogen sulfide gas from the sulfur recovery facility to the processing plant;
The first supply pipe is provided with a concentration meter for measuring a hydrogen sulfide gas concentration on the sulfur recovery equipment side from the predetermined branch point,
In the first supply pipe and the second supply pipe, on / off of supply of hydrogen sulfide gas to the processing plant via the supply pipe is more on the processing plant side than the predetermined branch point. A hydrogen sulfide gas production plant characterized in that an ON / OFF valve is provided, and a control valve is provided between the predetermined branch point and the ON / OFF valve provided in the second supply pipe. system.   It further has a blowdown facility for discharging waste hydrogen sulfide gas generated in the cooling facility, and has a pipe for supplying the waste hydrogen sulfide gas to the treatment plant from an outlet of the blowdown facility. The hydrogen sulfide gas production plant system according to claim 1.   3. The sulfide according to claim 1, wherein the production plant of each system is connected to a production plant of another system via the first supply pipe and the second supply pipe, respectively. Hydrogen gas production plant system.   It is adjusted by the control valve so that the weighted average value of the concentration of hydrogen sulfide gas when the hydrogen sulfide gas supplied from the manufacturing plant of each system to the processing plant is mixed is 85% by volume or more. The hydrogen sulfide gas production plant system according to claim 3, wherein   5. The nitrogen gas is supplied from the lower part of the reaction facility when a periodic inspection or trouble occurs in any of the plurality of manufacturing plants or when the manufacturing plant is started up. 2. A hydrogen sulfide gas production plant system according to item 1.   When hydrogen sulfide gas having a lower concentration than normal is generated when the operation of any of the plurality of manufacturing plants is stopped, the manufacturing plant that has stopped the operation is provided in the first supply pipe. The low concentration hydrogen sulfide gas is collected through the second supply pipe by closing the ON / OFF valve and opening the ON / OFF valve provided in the second supply pipe. The hydrogen sulfide gas production plant system according to any one of claims 1 to 5.   The said processing plant is a dezincification process plant which forms zinc sulfide in the hydrometallurgy method of nickel oxide ore, or a sulfidation process plant which forms nickel and cobalt mixed sulfide. A hydrogen sulfide gas production plant system according to any one of the preceding claims. At least a reaction facility for generating hydrogen sulfide gas with sulfur and hydrogen gas, a plurality of cooling facilities for cooling the generated hydrogen sulfide gas, and a sulfur recovery facility for recovering sulfur contained in the hydrogen sulfide gas. A method for recovering and using hydrogen sulfide gas in a hydrogen sulfide gas production plant system having a plurality of hydrogen sulfide gas production plants,
Each system of hydrogen sulfide gas production plant is
A first supply pipe for supplying the hydrogen sulfide gas after sulfur is recovered by the sulfur recovery facility to a treatment plant using the hydrogen sulfide gas;
A second supply pipe that branches at a predetermined location in the first supply pipe and supplies hydrogen sulfide gas from the sulfur recovery facility to the processing plant;
The first supply pipe is provided with a concentration meter for measuring a hydrogen sulfide gas concentration on the sulfur recovery equipment side from the predetermined branch point,
In the first supply pipe and the second supply pipe, on / off of supply of hydrogen sulfide gas to the processing plant via the supply pipe is more on the processing plant side than the predetermined branch point. An ON / OFF valve is provided, and a control valve is provided between the predetermined branch point and the ON / OFF valve provided in the second supply pipe,
When hydrogen sulfide gas having a lower concentration than normal is generated when the operation of any one of the plurality of manufacturing plants is stopped, the low concentration hydrogen sulfide gas is removed from the first concentration in the manufacturing plant where the operation is stopped. 2 is collected through the supply pipe and supplied to the processing plant while adjusting the flow rate with the control valve. In other production plants, the hydrogen sulfide gas produced with an increased production load is supplied first. A method for recovering and utilizing hydrogen sulfide gas, characterized in that the hydrogen sulfide gas is supplied to the treatment plant via a pipe.   The apparatus further comprises a blowdown facility for discharging waste hydrogen sulfide gas generated in the cooling facility, and supplying the waste hydrogen sulfide gas to the treatment plant through a pipe connected to an outlet of the blowdown facility. The method for recovering and using hydrogen sulfide gas according to claim 8.   The sulfide plant according to claim 8 or 9, wherein the production plant of each system is connected to the production plant of another system via the first supply pipe and the second supply pipe, respectively. How to recover and use hydrogen gas.   Adjusting the control valve so that the weighted average value of the concentration of the hydrogen sulfide gas when mixing the hydrogen sulfide gas supplied from the manufacturing plant of each system to the processing plant is 85% by volume or more. The method for recovering and using hydrogen sulfide gas according to claim 10.   The nitrogen gas is supplied from the lower part of the reaction facility when a periodic inspection or trouble occurs in any of the plurality of manufacturing plants or when the manufacturing plant is started up. 2. A method for recovering and using hydrogen sulfide gas according to item 1.   In the production plant that has stopped the operation, the ON / OFF valve provided in the first supply pipe is closed, and the ON / OFF valve provided in the second supply pipe is opened, whereby the first The method for recovering and using hydrogen sulfide gas according to any one of claims 8 to 12, wherein the low-concentration hydrogen sulfide gas is recovered through two supply pipes.   14. The process plant according to claim 8, wherein the treatment plant is a dezincification process plant for forming zinc sulfide or a sulfidation process plant for forming nickel and cobalt mixed sulfide in a hydrometallurgy method of nickel oxide ore. The method for recovering and using hydrogen sulfide gas according to any one of the preceding claims.

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